Improvement in screw-propellers



itat-ted *guette CHARLES ARLEN AND CHARLES GAUTSGHLYOF NEW YORK, N. Y.

Letters Patent No. 102,645, dated May 3, 1870.

IMP'RovnMENT IN scREw-PROPBLLERS.

The Schedule referred to in these Letters Patent and making part of thesame.

To all whom tt only concern Beit known that we, CHARLES Annex andCHARLES GAUTSCHI, both of the city, county, and State of New York, haveinvented a new and useful Improvement in Screw Propellers, of which thefollowing is a full, clear, and exact description, reference being hadto the accompanying drawing forming part of this specification, and inwhichl Figurel represents a side view, and

Figure 2 a section, taken longitudinally through its axis, of ascrew-propeller, constructed in accordance with my improvement.

Similar letters of reference indicate corresponding parts.

My invention consists in a novel construction of the screw, whereby thewater is more effectually restrained from being thrown out laterally byit, and is forced as a column in the rear ot' it, thereby malting thescrew more effective, and hy the water being drawn in toward the edge ofthe screw, preventing the washing of the banks in the propulsion ofvessels in canals or other narrow water-courses, for which my inventionis more particularly designed.

Referring to the accompanying drawing- A is the operating shaft, and Bthe screw proper, which is of plate-form, from its `junction with thehub a to its periphery, aud made to constitute an entire screw, ascontradistiuguished from screw sections carried by independent arms.

The same may be of any desiredl pitch and coliformation, as regardsincrease, relativelyto its hub or vouter edge.

The outer edge of said screw or screw-'plate is provided with reverseflanges b b, which are constructed to forni a hollow, o, somewhat of theshape of a V, around the outer edge ofthe 'plate or body of the screw.

Such flanges are not mere or detached sections, nor yet made toconstitute a ring or close baud, but form an entire spiral in commonwith the plate B, and

operate much more efectually to concentrate or cir-x cumscribe'andretain, as a column or confinedhody having its axis in the same linewith that of the operating shaft, the water thrown out by the screw,

which not only .adds to the etliciency of the propeller'` but diminishesside wash or action of the water, and

this latter advantage is still more perfectly attained by the hollow o,between the flanges around the outer edge of the' plate or body of thescrew,by reason of the diminished velocit-y of the bottom of the hollowas compared with the outer edges or surfaces of the flanges, whichinducesvsuction ofthe water into the hollow, and causes it to hug or.follow 'the flanged portion of the. propeller, as the latter isrotated.

\Vhat is here claimed, and desired to be secured by Letters Patent, is YThe spirally arranged flanges b I1, constructed to form a hollow, c,around the outer edge of the spiral plate B, essentially as, shown anddescribed.

GHS'. ARLEN. CHS. GAUTSCHI.

Witnesses:

FRED. HAINEs, R. E. RABEAU.

